Goldfish produce 3x the ammonia/waste of tropical fish of equal mass. True or false?

  • We are currently upgrading MFK. thanks! -neo

knifegill

Peacock Bass
MFK Member
Sep 19, 2005
8,782
112
120
43
Oscar Tummy
Okay, I've had this pounded into my head forever but is it really true? Factors I put forth which may perpetuate this idea:

1) Most goldfish are sold as rapidly growing babies with high metabolisms.
2) On the whole, they are fed nasty filler foods that would make a tank trashy no matter what ate them.
3) They are often kept my newbies who overfeed.
4) They are often put into very small tanks and crowded nearly to death in holding tanks.

I mean, If I put a 2" goldfish in one 30 gallon tank and a 2"...I don't know, token vegetarian/omnivorous SA cichlid in another and fed them the same food (though the goldfish would have to be at a cooler temp) shouldn't I see the same amount of waste made?

To satisfy the metabolic needs of a goldfish, is one truly doomed to have to deal with more waste than a tropical fish of the same basic growth rate, adult size and dietary needs? Do they really magically produce extra ammonia above and beyond what they would be perceived to be capable of producing?
 
I believe because of the way goldfish have been selectively bread they have some special dietary needs, and when fed normal food produce more "waste" because there body cant use it effectively...then that waste breaks down and produces ammonia.
 
Are you sure about that? Have you actually seen/tested for it and observed that it happens?
 
Does a goldfish have a stomach? I think i heard once they did not so that could be why they produce more waste .
 
Of course they have a stomach.
 
slimmer;4630277; said:
Does a goldfish have a stomach? I think i heard once they did not so that could be why they produce more waste .
No, they don't. And you do have a valid point on that.:thumbsup:

Here's the internal anatomy article for goldfish. For those who are squeamish with necropsy, you're warned.;)

http://thegab.org/Goldfish/goldfish-internal-anatomy.html

And here's an interesting one. Even though the goldfish excrete wastes as fast as they eat, a large portion remains undigested in which case they try to chew and swallow again until everything is digested. Gross but it's true.

More articles below for digestion and nutrition.

http://thegab.org/Goldfish/goldfish-nutrition-part-1-the-natural-diet-and-digestive-processes.html

http://thegab.org/Goldfish/goldfish-nutrition-part-2-food-and-nutrition.html
 
Nighttouch;4630312; said:
Of course they have a stomach.
The answer is incorrect. They rely on their enzymes and bacteria to digest their foods since they do NOT have stomach.
 
MonsterFishKeepers.com